The invention relates to improvements in methods of and in apparatus for ascertaining the times which elapse while one or more participants (such as humans, animals, motor vehicles, sailboats, bicycles and/or others) in a race or another contest cover a distance between a starting line and a finish line.
It is already known to employ a camera which takes pictures of the finish line at certain intervals in order to furnish evidence of the sequence in which the contestants in a race reach the finish line. It is also known to connect the signal transmitting outlet of the camera with a recording unit which records the pictures so that the outcome of the race can be judged after completion of the actual contest. It was further proposed to employ a timing pulse generator which is started in response to the signal from a photocell, a starter pistol or the like and furnishes signals which denote the time and are imaged onto the pictures of the finish line, and to utilize a photoelectronic detector which generates a signal whenever the winner crosses the finish line or whenever the finish line is crossed by an also ran who or which is not overlapped by the preceding contestant or contestants. In many instances, the camera is designed to take pictures at intervals of two or four hundredths of a second.
The means for recording the pictures can include a video recorder, a video printer and/or a display unit with a screen which displays successively formed pictures of the finish line.
A method and an apparatus of the above outlined character are disclosed, for example, in German Pat. No. 25 35 539 to Masse et al. A drawback of the patented method and apparatus is that the times of taking successive pictures might not always coincide with the times which are recorded on the respective pictures and are supposed to denote the actual times of picture taking. This can be attributable to the fact that the intervals between the taking of successive pictures do not always coincide with the timing of generation of signals which are indicative of time and are imaged on the pictures. Therefore, the patented method and apparatus are designed with a view to ensure that the starting pulse coincide with a synchronizing pulse of the camera; this is intended to ensure that the timing of picture taking will coincide with the timing of the generation of signals which denote time and are imaged on the pictures. In other words, the starting pulse should always coincide with a synchronizing pulse of the camera. The next-following synchronizing pulses of the camera for the taking of individual pictures are thereupon determined by the timing signal of the timing pulse generator.
It follows that the timing pulse generator must perform the additional task of determining the frequency of picture taking by the camera. The user or operator of the camera is in no position to ascertain whether or not this is always the case, i.e., whether or not the timing pulse generator is capable of invariably (even in the event of certain disturbances) accurately regulating the timing of picture taking. In other words, the user or the operator of the patented apparatus is not in a position to know whether or not the timing pulse generator has carried out the necessary adjustments with regard to the starting signal not later than when the contestant or contestants cross the finish line. Consequently, the patented apparatus is intended to but cannot always ensure exact coincidence between the time-representing signals and the times of picture taking.
Another drawback of the patented method and apparatus is that it is necessary to employ a specially designed camera, namely a camera which can be synchronized from the outside. Such specially designed cameras are much more expensive than commercially available series-produced cameras. Moreover, the specially designed camera must be used jointly with a recorder, even for the purposes of training. Still further, if a specially designed camera is damaged or is out of commission for other reasons, it takes much time to obtain an equivalent camera from a maker who specializes in the production and distribution of cameras with externally mounted synchronizing systems.